International Journal of Cancer Research1811-97271811-9735Academic Journals Inc.10.3923/ijcr.2008.81.91AbdelmeguidN.E. MostafaM.H. Abdel-MoneimA.M. BadawiA.F. ZeinabN.S. Abou 3200843The mammary gland cells of Sprague Dawley rats treated
with melatonin and/or tamoxifen were analyzed for apoptosis and ultrastructural
damage using transmission electron microscopy. The alterations of p53
expression were determined by western blotting. The experiment lasted
for 8 weeks where animals were subcutaneously injected with melatonin
(0.5 mg/rat daily) and/or tamoxifen (2.5 mg/rat twice a week). It is of
considerable interest that the doses used were equivalent to human therapeutic
doses reported previously. Obvious features of apoptosis due to melatonin
treatment were noticed. These included irregularities of nuclear shapes,
clumping and margination of nuclear chromatin and dilatation of the nuclear
envelope forming nuclear blebs. Electron micrographs of tamoxifen treated
mammary gland showed that there were occasional irregularities in nuclear
shape and chromatin distribution. Melatonin/tamoxifen administration resulted
in normal cellular and nuclear morphology with normal chromatin distribution.
In addition, pyknotic cells increased in frequency, yet this value was
less compared to melatonin treated group as well as tamoxifen treated
group. On the other hand, melatonin resulted in insignificant increase
of p53 expression compared to control while tamoxifen treatment revealed
p53 expression similar to control group. In melatonin/tamoxifen treated
group, p53 expression was almost confounded greatly to control group.
It could be concluded that the synergetic interaction between melatonin
and tamoxifen on the expression of p53 is weakly evident on normal mammary
gland tissue.]]>Bast, R.C., D.W. Kufe, R.E. Pollock, R.R. Weichselbaum, J.F. Holland and E. Frei,20005th Edn.,Blask, D.E., D.B. Pelletier and S.M. Hill,1991in vivo.]]>117526532Blask, D.E., R.T. Dauchy, L.A. Sauer, J.A. Krause and G.C. Brainard,200225256Bradford, M.M.,197672248254Chen, Y.Q., S.C. Cipriano, J.M. Arenkiel and F.R. Miller,19955545364539Cos, S. and E.J. Sanchez-Barcelo,200021133170Cos, S. and E.J. Sanchez-Barcelo,200015637647DiSaria, P.J., E.A. Grosen and T. Kurosaki,199617414941498Fisher, B., J.P. Costantino, C.K. Redmond, E.R. Fisher, D.L. Wickerham and W.M. Cronin,199486527537Greaves, P., R. Goonetilleke, G. Nunn, J. Topham and T. Orton,19935339193924Hard, G.C., M.J. Iatropoulos, K. Jordan, L. Radil, O.P. Kaltenberg, A.R. Imondi and G.M. Williams,19935345344541Hengartner, M.O.,2000407770776Jordan, V.C.,199015125136Jang, T.J., M.S. Kang, H. Kim, D.H. Kim, J.I. Lee and J.R. Kim,2000Cip1 associated with decreased expression of p27Kip1 in chemically induced rat mammary carcinogenesis.]]>9112221232Kedar, R.P., T.H. Bourne, T.J. Powles, W.P. Collins, S.E. Ashley, D.O. Cosgrove and S. Campbell,199434313181321Keyomarsi, K., N. O’Leary, G. Molnar, E. Lees, H.J. Fingert and A.B. Pardee,199454380385Kothari, A., A. Borges and A. Ingle,19971115966Kubatka, P., B. Bojkova and K. Mocikova-Kalicka,200147510Kulesz-Martin, M.F., B. Lisafeld, H. Huang, N.D. Kisiel and L. Lee,19941416981708Laemmli, U.K.,1970227680685Ljungman, M., H.M. O’Hagan and M.T. Paulsen,20012059645971Massion, A.O., J. Teas, J.R. Hebert, M.D. Wertheimer and J. Kabat-Zinn,1995443946Martindale, D.,20012851920Mediavilla, M.D., S. Cos and E.J. Sanchez-Barcelo,1999in vitro.]]>65415420Molis, T.M., L.L. Spriggs and S.M. Hill,1994816811690Nayfield, S.G., J.E. Karp, L.G. Ford, F.F. Dorr and B.S. Kramer,19918314501459Sanchez-Barcelo, E.J., S. Cos, R. Fernandez and M.D. Mediavilla,200310153159She, M.H., B.B. Chen, X.M. Wang and S.S. He,200423803807Shiu, S.Y.W., L. Li, J.N. Xu, C.S. Pang, J.T.Y. Wong and S.F. Pang, 199927183192Sionov, R.V. and Y. Haupt, 19991861456157Srinivasan, V., D.W. Spence, S.R. Pandi-Perumal, I. Trakht, A.I. Esquifino, D.P. Cardinali and G.J. Maestroni,2008108339350Thiantanawat, A., B.J. Long and A.M. Brodie,20036380378050Towbin, H., T. Staehelin and J. Gordon,19797643504354Truchet, I., S. Jozan, M. Guerrin, L. Mazzoloni, S. Vidal and A. Valette,2000254241248Wright, J.W., R.L. Stouffer and K.D. Rodland,20059036883695Wu, L. and A.J. Levine,19973441451Zhang, S.Y., J. Caamano, F. Cooper, X. Guo and A.J. Klein-Szanto,1994102695698Zhang, S., D.J. Hunter, S.E. Hankinson, E.L. Giovannucci, B.A. Rosner, G.A. Colditz, F.E. Speizer and W.C. Willet,199928116321637